title: Serial plasma choline measurements after cardiac arrest in patients undergoing mild therapeutic hypothermia: a prospective observational pilot trial.
abstract: OBJECTIVE
  Choline is related to phospholipid metabolism and is a marker for global ischaemia with a small reference range in healthy volunteers. The aim of our study was to characterize the early kinetics of plasma free choline in patients after cardiac arrest. Additionally, we investigated the potential of plasma free choline to predict neurological outcome.
  
  
  METHODS
  Twenty patients admitted to our medical intensive care unit were included in this prospective, observational trial. All patients were enrolled between May 2010 and May 2011. They received post cardiac arrest treatment including mild therapeutic hypothermia which was initiated with a combination of cold fluid and a feedback surface cooling device according to current guidelines. Sixteen blood samples per patient were analysed for plasma free choline levels within the first week after resuscitation. Choline was detected by liquid chromatography-tandem mass spectrometry.
  
  
  RESULTS
  Most patients showed elevated choline levels on admission (median 14.8 µmol/L; interquartile range; IQR 9.9-20.1) which subsequently decreased. 48 hours after cardiac arrest choline levels in all patients reached subnormal levels at a median of 4.0 µmol/L (IQR 3-4.9; p = 0.001). Subsequently, choline levels normalized within seven days. There was no significant difference in choline levels when groups were analyzed in relation to neurological outcome.
  
  
  CONCLUSIONS
  Our data indicate a choline deficiency in the early postresucitation phase. This could potentially result in impaired cell membrane recovery. The detailed characterization of the early choline time course may aid in planning of choline supplementation trials. In a limited number of patients, choline was not promising as a biomarker for outcome prediction.
authors.affiliation: Department of Intensive Care Medicine and Nephrology, Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Storm
authors.forename: Oliver
authors.initials: O
authors.lastname: Danne
authors.forename: Per Magne
authors.initials: PM
authors.lastname: Ueland
authors.forename: Christoph
authors.initials: C
authors.lastname: Leithner
authors.forename: Dietrich
authors.initials: D
authors.lastname: Hasper
authors.forename: Tim
authors.initials: T
authors.lastname: Schroeder
mesh_terms: D015415:Biomarkers / Q000097:blood*; D002794:Choline / Q000097:blood*; D005858:Germany; D006323:Heart Arrest / Q000097:blood* / Q000628:therapy*; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D007511:Ischemia / Q000097:blood* / Q000175:diagnosis; D010865:Pilot Projects; D011446:Prospective Studies; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D002794:Choline